The present invention relates to a method, and also apparatus, for providing ecological protection with respect to equipment using a halogenated hydrocarbon.
Halogenated hydrocarbons, or halocarbons, are chemical compounds of organic origin based on hydrocarbon chains in which hydrogen atoms are substituted with halogen atoms such as fluorine, chlorine, bromine and iodine. These chemical substances (liquids and gases) have been found in the last 40 years to have a vast range of industrial applications in areas such as: air-conditioning and refrigeration, cleaning and degreasing processess, organic extracting solvents, fire-retardant additives, fire extinguishing agents, aerosol propellants, foam blowing agents, and various intermediate and precursors in organic syntheses.
Since the worrying discovery of the "hole" in the ozone layer in the atmosphere over the Antarctic Pole in 1986, the world-wide community of environmental scientists has accumulated much data on the ozone depleting substances found in that region. It was found that various materials reach the stratosphere, react with the ozone, and dissociate it to oxygen molecules and atoms. These materials have been classified according to their ability to destroy the ozone in the atmosphere. A mathematical parameter, called the "Ozone Depletion Potential (ODP)", was devised to measure and compare the ozone destruction capability of materials: the higher the ODP, the more potentially dangerous the substance.
Among the materials with high ODP are the halocarbons, especially the CFC (chlorofluorocarbons) and the Halons, because of their high content of active halogen atoms that act on the ozone molecule and cause its dissociation. Theses materials, being stable for many years (their life-time is well over 20 years), pose a continuous threat to the ozone layer since their release into the atmosphere is inevitable. Even closed circuit systems (such as air conditioning and refrigeration systems), and certainly open systems, release these materials into the atmosphere when tested, calibrated, repaired, maintained, or malfunctioning.
However these halocarbon materials are of utmost importance in military and civilian applications and for industrial and domestic purposes. So far no comparable alternative substance has been found, nor seems likely to be developed in the near future, because of the unique chemical and physical characteristics of these substances.
In order to continue the necessary use of halocarbons in its various applications, one must find a method to destroy these materials once they are likely to be released into the atmosphere, whether the release is on purpose or accidental. Various methods (chemical and physical)could be applied for the halocarbon's destruction, such as heat decomposition (incineration), adsorbance, absorbance, chemical decomposition with catalysts, metal scrubbing, pyrolysis, wet air oxidation and supercritical water oxidation. The only demonstrated technology which is currently being used is incineration. However, these methods do not specifically destroy the active site of the material, i.e. the halogen atom, and therefore allow many potential hazardous by-products to be released into the atmosphere. These by-products may still contain damaging amounts of halogenated hydrocarbons with high ODP and long life-time.